Refrigeration



Feb. 8, 1938. G. F. zELLHoEFER 2,107,320

REFRIGERATION r Filed Deo. 5, 1955 2 Sheets-Sheet 2 INVENTOR.` GMW/v F. 25u H05/5R ATTORNEY.

Patented Feb. s, '193e UNITED STATES PATENT OFFICE asr'mGEasrxoN Glenn F.. Zellhoefer, Bloomington, Ill.

Application December 5, 1935, Serial No. 53,027

a claims. v(on. sz-11s) lincludes a gaseous refrigerant and a liquid solvent adapted-to form a solution with the gaseous refrigerant, and the-apparatus therefore includes an absorber in which the solution is formed, a heater within which the 'gaseous refrigerant is boiled off or expelled, a rectifier through which the expelledgaseous refrigerant passes on its way to a condenser wherein the refrigerant is converted into a liquid, a cooling coil or evaporator into which the liquid refrigerant is dis- 16 charged under reduced pressure to retur'n to thegaseous state absorbing heat from the atmosphere surrounding the cooling element, and means for circulating the solution from the absorber to the heater and returning both the solvent after the 20 refrigerant has been expelled in the heater and i the refrigerant vapors from the evaporator to the absorber. I v

The rectifier is provided to free and. return to the heater such of the vaporous solvent or solugg tion in vapor form that may be carried over with the boiled-offer expelled refrigerant before entering the condenser. It is an object of this invention to provide an improved rectifierforthe purpose above stated. l S so With this and other objects in view, reference is made to the accompanying sheets of drawings illustrating a form ofvthis improved rectiiler for an absorption refrigeration apparatus Awith the understanding that minor changesmaybe made 3; withoutA departing from the scope thereof.

In the drawings: I I Figure l is a view in vertical transverse section taken through the end of an absorptionrefrigeration heater embodying the improved rectifier. as 40 on the 'lines i-i, Figure 2, showing'the nearI manifold in elevation and with parts broken away.

Figure 2 is a view in central vertical longitudinal section taken-on the line 2 2, Figure l.

The heater and rectier illustrated form a 4g part oi' the system of an absorption refrigeration apparatus auch as 'generally disclosed inthis applicant's ,prior co-pending application Serial No. 736,232, filed July 20,19%. whichshas matured into PatentNo. v2,0lili06, granted Nov. 24, 1936.

I so It hasbeen discovered when dichloromonouoromethane, or a chemical of similar characteristics, is used as the refrigerant.'and monoethyl ether of diethyleneglycol acetate, or a chemical of similar characteristics, as the solvent,.as disclosed in this applicants prior co-pending application Serial No. '756,9'7'7,- filed December 11, 1934 which has matured into Patent No. 2,040,895, granted May19, 1936, in an absorption refrigeration system, a problem yarises in separating the solvent from the refrigerant before the gaseous 5 refrigerant is discharged into the condenser different from the conventional commercial ammonia-water absorption apparatus.

The boiling point of the specified solventis between 410 F. and 435 F. at atmospheric pres- 10 sure, and the boiling point of the specified refrigerant is between 49 F. and 50 F.- at atmospheric pressure. At 230 F. the vapor pressure of the solvent is approximately 20mm., and at 180 F. the vapor pressure is approximately 1.5 mm. 15 From-this data it is seen that if the vapors of the solvent are cooled, after leaving the heater, to 180 F., it will theoretically condense out essentially all of the solvent vapors under the operating conditions of the apparatus, which is ordinarily 20 between and 30 lbs. o f pressure in the heater.

This improved rectiley is so constructed as to provide sufficient eliminator surface 'through which the vapors pass and chill the vapors to between 140 F. and 180 F. after they leave the 25 heater, and then provide an additional eliminator surface to insure thatV no particles of cony densed solvent vapors carry over with the refrigerant vapors into the condenser.

The embodiment of this invention illustrated includes a cylindrical heater I mounting a plu-Y rality of steam pipes 2 arranged between manifolds 3 and t at the opposite ends of the heater with the manifold 3 connected to the source of steam, not shown, by pipe 5. It is preferable to 35 mount the manifold #i at a lower level than manifold -3 so thatthe condensate'` will drain from the pipes Z-thereinto and from which the condensate is removed by the pipe t leading from the bottom of said manifold. The manifolds 3 and i are 40 positioned within the heater sothat approximately one-third of the pipes 2 are above the longitudinal center-line and the pipes are preferably provided with a plurality of closely spaced radiating fins in the form of plates l. I

A bank of nozzles for spraying the solution or 'refrigerant mixture over the heater steam pipes 2 is provided in spaced-apart relation from the top 'of the heater l by mounting a plurality of nozzles t upon a series of parallel pipes 9 ex- 50 tending longitudinally of the heater from a manifold illat one endthereof connected by pipe il to the source of refrigerant mixture or solution supply, n ot shown.

The rectier proper is formed of a cylindrical casing I2 preferably arranged longitudinally above the top of the heater I'of the same length but of considerably less diameter than the heater and in free communication with the interior of the heater, as by the plurality of large cylindrical conduits I3 spaced a short distance apart. A' plurality of eliminators .are provided preferably between the bankof nozzles and the top of the heater, and below and above a central longitudinal coil of pipe for circulating 'a cooling rnedium ,through the rectifier to reduce the temperaturev of the refrigerant vapors before the gaseous refrigerant passes through the discharge opening Il of the rectifier to be conducted by a pipe, not shown, to the condenser. The cooling coil preferably includes a plurality of parallel rows of pipes I5 bent back upon thereabove, as shown, with their respective ends connected to manifolds Iand I1 in communication with the supply and return lines ofthe circulating fluid, not shown.

The pipes I5 are preferably provided with a plurality of closely spaced radiating fins i`n the form of plates I8. It is also preferable to'provide a `baille plate I9 at the end of the heater to direct the spray from the end nozzle 8 upon the pipes 2 of the heater and a baille plate 20 at the .end of the rectifier I2 spaced apartfrom the discharge end to direct the refrigerant vapors over the cooling coil.

The elirninators are preferablycomposed of a plurality -of small spherical bodies 2I of glazed refractory material held in close contact with each other between expanded metal plates 22.

It is preferable to construct the elirninators in theheater with the bottom expanded metal plate 22 supported upon the top of the parallel solution pipes 9 and with the top expanded metal platev 22 spaced apart from` the top of the heater to form a chamber 23 thereabove which communicates with the rectifier I2 through conduits I3. It is also preferable to provide the eliminators above and\beiow the cooling coil I I in the rectifier I2 ywith thelower expanded metal plate 22 of the Y lower eliminator andthe upper expanded metal plate 22 ofthe upper eliminator spaced apart l from the adjacent' rectifier walls to provide a chamber 24 at the bottom in `communication with the chamber 23 above the heater' eliminator and a chamber 25 above the upper eliminator in communication with the rectifier discharge IL If sufficient elimination of solventfrom therefrigerantvaporsfis not effected, the solvent is carried over into the condenser and then into the evaporator, where a very small percentage of solventwill hold in solution a relatively large amount of refrigerant under the reduced pressure in the cooling coil orevaporator, the fullvaporization of L fromthe rectifier to the percent of solvent 'vapors which are precipitated out in passing over the cooling'coil so that there remains at a temperature of 140 F. to 180 F. approximately 115 to 1/4 of 1 per cent of solvent in the refrigerant vapors leaving the rectifier I2,

which will not appreciably detract from opera- 'tion of the evaporator.

'rhecuminator mustrated and described nerein causes any refluxing that the otherwise wasted heat of .the hot vapors to revaporize a part of the\ solvent that has been eliminated from the refrigerant vapors as it gravitates downward to the heating coil. \,When solvents' having sufficiently higher boiling points are employed, the rectier cooling coils I5 may be omitted and the vapors collecting in the chamber 23l at the ltop of the'heater I may be conducted by one or more conduits directly to the condenser. Such solvents may be dimethyl takes place toutilize gas that dissolves in the ether of tetraethylene glycol, diethyl ether of tetraethylene glycol, and methyl ethyl ether of tetraethylene glycol which have a vapor pressure of less than 3 mm. at 240 F. thereby insuring less than 1 per cent of solvent in 500 parts oi refrigerant even though no cooling coil is used, but adequate illuminating surfaces must be employed. 'I'hose solvents are in other respects just as good or better than the ethyl ether of diethylene glycol but inherently more expensive under the present methods of production. When a cooling coil is temperature of the coil used in the rectifier, the is controlled kin accordance with .the characteristics of the solvent emto be carried along in the stream of outgoing refrigerant v/apors in leaving the heater on the way the liquid refrigerant will not occur, and consevquentlyftliere is a'losslof cooling effect. It has been found in practice with the use of the refrigerant .and solvent specified if the nozzles B lfor spraying the refrigerant mixture or-solution @are located approximately 2% to 3 inches above ev heating coils 2, the'refrigerant vapors passl through" th e spray and into the eliminator above the nozzle'bank. In leaving this eliminator, the refrigerant will carry with it approximately'21/2 per cent of solvent in the form of line spray and vapor. The chamber 23 at the top-of the heater affords ample space for equalization of flow of said` vaporsthrough said first eliminator and through the conduits I3 into the chamber 24 to pass through the eliminator orithe under side of the cooling coil'. Irileaving second eliminator, the'vapor willfcarry approximately 1 to 11/4* to the condenser.

The characteristics of these chemicals are such that even with one lower boiling -point solvent. such as ethyl ether of' diethylene glycol, the amount of cooling required to insure a satisfactory separation of solvent and refrigerant is small provided any suspended particles of liquid solvent are separated from the gaseous refrigerant before the refrigerant is subjected to cooling; On the other hand, a failure to satisfactorily separate the suspended solvent liquid particles from the gaseous refrigerant before attempting to cool re-- cent of heat sults in waste of a very -large per necessary` to operate the equipment.

What I claim is: s l' l. In a heater or generator forv an absorption refrigeration apparatus, employing a volatile.

chemically stable, halogenated hydrocarbon..

forming a dense vapor irrithe'heater, as the refrigerant, and a solvent therefor having a low surface tension, `the combination of means within the heater f or'freeing such vaporous-solvent and solution f'OirLthe 'vaporous refrigerant distilling from the solution and allow the freed solvent and solution to descend by gravity into the heater, said means including an eliminator spaced apart from the top of the heater comprising a plurality chemically stable, halogenated hydrocarbon as the refrigerant, and a solvent therefor, means for eliminating the vapors of the solvent and solution from the vaporous refrigerant inpassing from the heater, including a rectifying chamber arranged above and in free communication withl the top of the heaterand a cooling coil arranged with said chamber, the temperature of which is sulclent to' precipitate out such vapors of solvent or solution that may be carried over with the refrigerant vapors, an eliminator spaced apart from the top of .the heater comprising a plurality of closely spaced spherical bodies of glazed refractory material.

3. The structure of claim 2 wherein eliminators are spaced apart from the top and bottom of said chamber and arranged on both sides of said cooling coil.

GLENN F. ZELLHOEFER. 

